This invention relates to a fuel-metering system for internal combustion engines, which system comprises a fuel reservoir and a fuel line leading from the said reservoir to a suction tube for the intake of air, and wherein the amount of fuel which is metered into the amount of air flowing through the suction tube, is determined by the pressures prevailing in the fuel reservoir and in the suction tube, and the pressure in the fuel reservoir is changeable by means which are controlled in dependence on engine data, and in particular by the output signal of a measuring probe which detects the composition of the exhaust gas.
In accordance with the present day technical requirements, such fuel-metering systems serve to provide automatically a favorable fuel/air mixture ratio for all operating conditions in a combustion engine, so as to burn up the fuel as completely as possible, and thereby to avoid or greatly diminish the formation of toxic exhaust gases, while ensuring the highest possible performance of the internal combustion engine with the smallest possible consumption of fuel. To this end, the amount of fuel must be metered very precisely in accordance with the particular requirements of each operating condition of the internal combustion engine. Hence, the most favorable mean proportionally value between air amount and fuel amount should be adjustable in dependence on engine data, and in particular on exhaust gas data, which is achieved in the above-described fuelmetering system by changing the pressure in the fuel reservoir.